1 Introduction
Fukushima nuclear power plant accident has highlighted insufficient preparedness
for unexpected events in many systems. Electricity supply system is one of them.
By the shut-down of nuclear power plants and thermal plants in Kanto region and
Tohoku region, rolling blackout was taken place to compensate for supply capacity
shortage, which was the first time in Japan after the World War II. In addition, the
Japanese government issued the restriction of electricity use against the large-lot
electricity users in summer 2012 for the same reason. These policies and voluntary
demand side management prevent massive blackout, but Japanese society had
suffered heavy social and economic damages. Therefore, in the future power generation planning, preparation for power plants’ successive shut-down should be
considered so that social and economic damages caused by the shut-down will be
the smallest. That is to say, implementation of seismic resilience into electricity
supply system is necessary.
Resilience in this context refers to the adaptive capacity of a system to absorb
changes and to maintain its functionality. From a quantitative perspective, resilience
can be enhanced by the following three measures: “Reduces failure probability,”
“Reduced consequences from failures,” and “Reduces time to recovery.”
Furthermore, enhancement measures of seismic resilience can be classified
according to the following four properties [1]:
• Robustness: strength, or the ability of elements, systems, and other units of
analysis to withstand a given level of stress or demand without suffering
degradation or loss of function
• Redundancy: the extent to which elements, systems or other units of analysis
exit that are substitutable, i.e., capable of satisfying functional requirements in
the event of disruption, degradation, or loss of functionality
• Resourcefulness: the capacity to identify problems, establish priorities, and
mobilize resources when conditions exit that threaten to disrupt some element,
system, or other unit of analysis; resourcefulness can be further conceptualized
as consisting of the ability to apply material (i.e., monetary, physical, technological, and informational) and human resources to meet established priorities
and achieve goals
• Rapidity: the capacity to meet priorities and achieve goals in a timely manner in
order to contain losses and avoid future disruption
Hence, seismic resilience enhancement measures in electricity supply system can
be presented in accordance with these four properties. For example, robustness in
electricity supply system can be enhanced by improving power plants’ earthquake
resistant capacity. Alternative power resources enhance redundancy. Demand side
management enhances resourcefulness. Then, restoration plans enhance rapidity. Of
course, it must be noted that these example are illustrative only. Many other
researches which contribute the enhancement of seismic resilience also are classified into the four properties. The classification gives systematic understanding
290
H. Matsuzawa et al.
Fukushima nuclear power plant accident has highlighted insufficient preparedness
for unexpected events in many systems. Electricity supply system is one of them.
By the shut-down of nuclear power plants and thermal plants in Kanto region and
Tohoku region, rolling blackout was taken place to compensate for supply capacity
shortage, which was the first time in Japan after the World War II. In addition, the
Japanese government issued the restriction of electricity use against the large-lot
electricity users in summer 2012 for the same reason. These policies and voluntary
demand side management prevent massive blackout, but Japanese society had
suffered heavy social and economic damages. Therefore, in the future power generation planning, preparation for power plants’ successive shut-down should be
considered so that social and economic damages caused by the shut-down will be
the smallest. That is to say, implementation of seismic resilience into electricity
supply system is necessary.
Resilience in this context refers to the adaptive capacity of a system to absorb
changes and to maintain its functionality. From a quantitative perspective, resilience
can be enhanced by the following three measures: “Reduces failure probability,”
“Reduced consequences from failures,” and “Reduces time to recovery.”
Furthermore, enhancement measures of seismic resilience can be classified
according to the following four properties [1]:
• Robustness: strength, or the ability of elements, systems, and other units of
analysis to withstand a given level of stress or demand without suffering
degradation or loss of function
• Redundancy: the extent to which elements, systems or other units of analysis
exit that are substitutable, i.e., capable of satisfying functional requirements in
the event of disruption, degradation, or loss of functionality
• Resourcefulness: the capacity to identify problems, establish priorities, and
mobilize resources when conditions exit that threaten to disrupt some element,
system, or other unit of analysis; resourcefulness can be further conceptualized
as consisting of the ability to apply material (i.e., monetary, physical, technological, and informational) and human resources to meet established priorities
and achieve goals
• Rapidity: the capacity to meet priorities and achieve goals in a timely manner in
order to contain losses and avoid future disruption
Hence, seismic resilience enhancement measures in electricity supply system can
be presented in accordance with these four properties. For example, robustness in
electricity supply system can be enhanced by improving power plants’ earthquake
resistant capacity. Alternative power resources enhance redundancy. Demand side
management enhances resourcefulness. Then, restoration plans enhance rapidity. Of
course, it must be noted that these example are illustrative only. Many other
researches which contribute the enhancement of seismic resilience also are classified into the four properties. The classification gives systematic understanding
290
H. Matsuzawa et al.